CN116942966A

CN116942966A - Disposable syringe needle

Info

Publication number: CN116942966A
Application number: CN202210405420.2A
Authority: CN
Inventors: 张立波
Original assignee: Tianjin Huahong Technology Co Ltd
Current assignee: Tianjin Huahong Technology Co Ltd
Priority date: 2022-04-18
Filing date: 2022-04-18
Publication date: 2023-10-27
Also published as: US20230330340A1; EP4265284A1

Abstract

The present invention provides a disposable injection needle comprising: a needle mount provided with a needle cannula extending axially therethrough; a first sheath having one end connected to one end of the needle mount to form an accommodating space between the first sheath and the needle mount; a second sheath, a portion of which is axially slidably located within the accommodation space; the inner core is arranged in the accommodating space and sleeved on the needle seat; and a spring adapted to provide an elastic force for axially moving the second sheath toward the outside of the accommodation space. The one end of the second sheath is sleeved on the inner core and is suitable for retracting towards the accommodating space based on external force so as to expose the needle tube. The disposable injection needle has the function of protecting the patient end, thereby avoiding the infection caused by injury to the human body and repeated use of the needle tip, and being convenient and quick to use.

Description

Disposable syringe needle

Technical Field

The invention relates to the field of medical appliances, in particular to a disposable injection needle.

Background

Insulin injection needles have been widely used as a means for treating diabetes, and have a main function of controlling blood sugar of a patient by injecting insulin into the body of the diabetic patient.

The common injection needle matched with the insulin injection pen in the market at present is formed by combining a large sheath, a small sheath, a needle seat, a needle tube and dialysis paper. The needle tip of the needle tube is always exposed after the large sheath and the small sheath are removed, so that the infection probability can be increased if some patients use the needle tube for the second time, or the used needle head is easy to accidentally injure other people to cause cross infection.

Disclosure of Invention

In order to alleviate or solve at least one aspect of the above problems, the present invention provides a disposable injection needle having a patient end protecting function, thereby avoiding infection caused by injury to a person and repeated use of the needle tip, and being convenient and quick to use.

According to an embodiment of the present invention, there is provided a disposable injection needle including: a needle mount provided with a needle cannula extending axially therethrough; a first sheath having one end connected to one end of the needle mount to form an accommodating space between the first sheath and the needle mount, the other end of the first sheath having a first opening; a second sheath having one end located in the accommodation space and the other end having a second opening and protruding from the first opening, a portion of the second sheath being axially slidably located in the accommodation space; the inner core is arranged in the accommodating space and sleeved on the needle seat, one end of the inner core is provided with a third opening, and the needle tube axially extends through the third opening and is suitable for being exposed through the second opening; and a spring adapted to provide an elastic force for axially moving the second sheath toward the outside of the accommodation space. The one end of the second sheath is sleeved on the inner core and is suitable for being retracted into the accommodating space to expose the needle tube based on the external force overcoming the elastic force of the spring. The other end of the inner core is provided with an inner core guide part extending radially, the needle seat is provided with a guide matching part, and the inner core guide part is matched with the guide matching part at the installation position of the inner core and the needle seat. The core guide portion moves along the guide engagement portion to guide the core to rotate in the circumferential direction based on the second sheath moving toward the accommodation space, and is adapted to move out of engagement with the guide engagement portion.

Further, the second sheath has a small diameter portion and a large diameter portion connected to each other in the axial direction, the small diameter portion and the large diameter portion forming a stepped surface at the connection, wherein the small diameter portion is adapted to protrude from the first opening to outside the first sheath, and a distal end of the small diameter portion has the second opening. The other end of the first sheath has a first blocking surface defining the first opening. The step surface is suitable for being in abutting fit with the first blocking surface, and the large-diameter part can be axially and slidably positioned in the accommodating space.

Optionally, the inner wall of the second sheath is provided with a blocking member extending in the axial direction, and the outer wall of the inner core is provided with a limiting guide groove extending in the axial direction. Based on the rotation of the inner core in the circumferential direction, the blocking member enters the limit guide groove.

In one embodiment, the limit groove includes a first groove portion and a second groove portion disposed along the axial direction, the first groove portion having a larger dimension in the circumferential direction than the second groove portion. Based on the circumferential rotation of the inner core, the blocking member is adapted to rotate axially and circumferentially from the first guide groove portion to the second guide groove portion and to be blocked in the second guide groove portion.

Optionally, a guide surface is disposed at an end of the first guide groove portion near the second guide groove portion, and a mating surface that mates with the guide surface is disposed at an end of the blocking member.

Optionally, the inner wall of the second sheath is provided with a plurality of the stoppers spaced apart from each other, and the outer wall of the inner core is provided with a plurality of the limit guide grooves spaced apart from each other. Each of the plurality of stops enters a corresponding one of the plurality of limit channels based on circumferential rotation of the inner core.

Further, both side walls of the limit groove in the circumferential direction extend to be close to the third opening to form a sheath blocking surface.

In one embodiment, the bottom of the needle mount is provided with a limiting plane, from which the guide engagement portion extends in the axial direction towards the first opening and is located at an edge of the limiting plane. After the axial rotation of the inner core is completed, the other end of the inner core abuts against the limiting plane to prevent the inner core from further axial movement. The needle seat is also provided with an inner core limiting part connected with the guiding matching part, and the inner core limiting part is suitable for preventing the inner core from further circumferential movement after the circumferential rotation is completed.

Optionally, the other end of the inner core is provided with a boss portion extending radially from a core body of the inner core, the inner core guide portion extends radially from an edge of the boss portion toward the needle mount, and the guide fitting portion is disposed radially outside the boss portion. The boss portion has a boss top surface and a boss bottom surface, one end of the spring abuts the boss top surface. After the circumferential rotation of the inner core is completed, the boss bottom surface or the inner core guide portion abuts against the limit plane.

Further, the guide engaging portion includes a planar guide portion and a slope guide portion extending obliquely from the planar guide portion to the limit plane. In the installation position of the inner core and the needle seat, the inner core guide part is matched with the plane guide part. Based on the second sheath moving toward the accommodation space, the core guide rotates in the circumferential direction from the planar guide to the ramp guide to guide the core to rotate in the circumferential direction, and the core guide is adapted to move out of engagement with the ramp guide.

In one embodiment, the needle holder may be provided with a plurality of the guide engaging portions, and the core stopper is a core stopper groove between two adjacent guide engaging portions of the plurality of guide engaging portions.

In another embodiment, the needle hub may further comprise a sheath blocking portion, which abuts the guide fitting portion, and which has a height in the axial direction greater than a height of the guide fitting portion in the axial direction, the sheath blocking portion being adapted to prevent the second sheath from moving toward the accommodation space.

In one embodiment, the hub is provided with a through hole at the center thereof through which the needle tube passes, and the hub is further provided with a hub rib extending from the through hole in the axial direction. The inner wall of the inner core is provided with a hub fitting portion extending in the axial direction, and the hub rib is fitted in the hub fitting portion and adapted to axially rotate in the hub fitting portion.

Optionally, the hub rib and the hub mating portion each have a stepped shape.

In one embodiment, the one end of the first sheath is provided with a base, and the inner wall of the base is provided with a transverse groove circumferentially arranged. The one end of needle file is provided with horizontal protruding muscle, horizontal protruding muscle is along radial surrounding arrangement in the outer wall of needle file, just horizontal protruding muscle cooperation is in horizontal inslot.

Further, the one end of the needle seat is also provided with a needle seat clamping groove extending along the axial direction, and the needle seat clamping groove is positioned on the outer wall of the needle seat. The inner wall of the base is also provided with a convex rib extending along the axial direction, and the convex rib is suitable for being matched in the needle seat clamping groove.

In another embodiment, the one end of the second sheath is provided with a sheath limiting groove formed on an outer wall of the second sheath. The inner wall of the first sheath is provided with a limiting convex rib extending along the axial direction, and the limiting convex rib is suitable for being matched in the sheath limiting groove.

Optionally, the sheath limiting groove includes a first limiting groove portion and a second limiting groove portion arranged along the axial direction, the first limiting groove portion having a triangular cross section, the second limiting groove portion having a rectangular cross section.

In one embodiment, the disposable injection needle may further comprise a third sheath externally sheathing the needle hub, the inner core, the first sheath and the second sheath.

Optionally, a first anti-rotation structure is arranged at the connection part between the third sheath and the needle seat, and a second anti-rotation structure is arranged at the connection part between the third sheath and the needle seat.

Further, the disposable injection needle may further include a sealing patch covering the opening of the third sheath.

Drawings

The above and other aspects and features of the present invention will become apparent from the following description of embodiments taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a disposable injection needle according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the disposable injection needle shown in FIG. 1;

fig. 3 and 4 are perspective views of a first sheath according to an embodiment of the present invention, respectively, from different perspectives;

fig. 5 and 6 are perspective views of a second sheath according to an embodiment of the present invention, respectively, from different perspectives;

fig. 7 and 8 are perspective views of an inner core according to an embodiment of the present invention, respectively, from different perspectives;

fig. 9 is a perspective view of the hub according to the embodiment of the present invention;

FIG. 10 is a schematic view of an assembly of a first sheath with a second sheath according to an embodiment of the invention;

fig. 11 is an assembled cross-sectional view of the inner core and the hub according to an embodiment of the present invention;

FIG. 12 is a schematic view of the disposable needle in an initial assembled state with a portion of the first sheath and the second sheath removed, according to an embodiment of the present invention;

FIG. 13 is a schematic view of a disposable needle in use with a portion of the first and second sheaths removed, according to an embodiment of the present invention;

FIG. 14 is a schematic view of a disposable injection needle in use with the needle cannula in the longest exposed state and with a portion removed to reveal internal structure, according to an embodiment of the present invention;

FIG. 15 is a schematic view of a disposable injection needle during use with the needle cannula in the longest exposed state and the first sheath removed, according to an embodiment of the present invention;

FIG. 16 is a schematic view of the disposable needle after use according to an embodiment of the present invention;

FIG. 17 is a schematic view of a disposable needle after use again subjected to a depressing force, with a portion removed to show the internal structure, according to an embodiment of the present invention; and

fig. 18 is a schematic view of the disposable needle shown in fig. 17 after removal of the first sheath and spring.

Detailed Description

The technical scheme of the invention is further specifically described below through examples and with reference to the accompanying drawings. In the specification, the same or similar reference numerals denote the same or similar components. The following description of embodiments of the present invention with reference to the accompanying drawings is intended to illustrate the general inventive concept and should not be taken as limiting the invention.

A disposable needle according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings, it being noted that some features or components are not specifically shown in the drawings for clarity of illustration.

Referring to fig. 1, the disposable injection needle of the embodiment of the present invention includes a needle holder 10, a first sheath 20, a second sheath 30, an inner core 40, and a spring 50. The needle hub 10 is provided with a needle cannula 60 extending axially therethrough. As shown in fig. 2 and 3, one end of the first sheath 20 is connected to one end of the needle mount 10 to form an accommodating space R between the first sheath 20 and the needle mount 10, and the other end of the first sheath 20 has a first opening 201. As shown in fig. 2 and 5, one end of the second sheath 30 is located in the accommodation space R, the other end of the second sheath 30 has a second opening 301 and protrudes from the first opening 201, and a portion of the second sheath is axially slidably located in the accommodation space R. As shown in fig. 2 and 7, the inner core 40 is disposed in the accommodating space R and is fitted over the needle holder 10, one end of the inner core 40 has a third opening 401, and the needle tube 60 extends axially through the third opening 401 and is adapted to be exposed via the second opening 301 (as shown in fig. 14). The spring 50 is adapted to provide an elastic force for axially moving the second sheath 30 toward the outer axis of the accommodating space R. The one end of the second sheath 30 is sleeved on the inner core 40 and adapted to retract toward the inside of the accommodating space R against the elastic force of the spring 50 based on the external force to expose the needle tube 60 (as shown in fig. 14). As shown in fig. 7, 9 and 12, the other end of the inner core 40 is provided with a radially extending inner core guide 402, and the needle mount 10 is provided with a guide mating portion. In the installed position of the core 40 with the needle mount 10, the core guide 402 mates with the guide mating portion, as shown in fig. 12. As shown in fig. 13-16, based on the movement of the second sheath 30 toward the accommodation space R, the core guide 402 moves along the guide engagement portion to guide the core 40 to rotate in the circumferential direction, and is adapted to move out of engagement with the guide engagement portion.

In an embodiment of the present invention, the hub 10 of the disposable injection needle is provided with the inner core 40, and the needle tube 60 axially extends through the third opening 401 of the inner core 40 and is exposed through the second opening 301 of the second sheath 30. In the initial assembled state of the disposable injection needle, for example, as shown in fig. 12, the one end of the second sheath 30 is sleeved on the inner core 40 and is located in the accommodating space R, and the one end of the first sheath 20 is connected to one end of the needle mount 10, and the other end is engaged with the second sheath 30. At this time, the inner core guide 402 of the inner core 40 is engaged with the guide engagement portion of the needle hub 10. When the disposable injection needle is used, after an external force is applied to the disposable injection needle, the second sheath 30 moves toward the needle holder 10, i.e., retracts toward the inside of the accommodating space R, under the external force, and thus thrust is generated to the inner core 40. Under this pushing force, the core 40 rotates circumferentially, so that the core guide 402 moves along the guide engagement portion to guide the core 40 to rotate in the circumferential direction to expose the needle tube, and continues to move out of engagement with the guide engagement portion to axially move the second sheath toward the outside of the accommodating space under the elastic force of the spring, thereby covering the needle tube to prevent secondary use and increase the infection probability.

Further, referring to fig. 5, the second sheath 30 has a small diameter portion 302 and a large diameter portion 303 connected to each other in the axial direction, the small diameter portion and the large diameter portion forming a step surface 304 at the connection. The small diameter portion 302 is adapted to protrude from the first opening 201 beyond the first sheath 20, and the distal end of the small diameter portion 302 has a second opening 301. In addition, as shown in fig. 3, the other end of the first sheath 20 has a first blocking surface 202 defining a first opening 201. The stepped surface 304 is adapted to be in abutting engagement with the first blocking surface 202 (as shown in fig. 2 and 12), and the large diameter portion 303 is axially slidably located within the accommodation space R.

As shown in fig. 6, 7 and 15, in one embodiment, the inner wall of the second sheath 30 is provided with a stopper 305 extending in the axial direction, and the outer wall of the inner core 40 is provided with a stopper guide groove 403 extending in the axial direction (as shown in fig. 18). Based on the rotation of the core 40 in the circumferential direction, the stopper 305 moves within the limit groove 403, as shown in fig. 13 and 15. Alternatively, the inner wall of the second sheath 30 may be provided with a plurality of stoppers 305 spaced apart from each other (as shown in fig. 6), the outer wall of the inner core 40 is provided with a plurality of stopper grooves 403 spaced apart from each other, and each of the plurality of stoppers 305 moves within a corresponding one of the plurality of stopper grooves 403 based on the circumferential rotation of the inner core 40.

In the embodiment of the present invention, as shown in fig. 7, the limit groove 403 may include a first groove portion 4031 and a second groove portion 4032 provided in the axial direction, the first groove portion having a larger dimension in the circumferential direction than the second groove portion. Based on the circumferential rotation of the inner core 40, the blocking member 305 is adapted to rotate axially and circumferentially from the first channel portion 4031 to the second channel portion 4032 and to be blocked in the second channel portion 4032, thereby preventing further rotation of the inner core, as shown in fig. 13-15. For example, when the core is rotated to engage the side wall of the stop 305 with the side wall of the limit channel 403, the core is prevented from further rotation.

Further alternatively, the end of the first channel portion 4031 near the second channel portion 4032 may be provided with a guide surface 4033 and the end of the blocking member 305 may be provided with a mating surface that mates with the guide surface 4033.

As shown in fig. 7, in the embodiment of the present invention, both side walls of the restricting groove 403 in the circumferential direction extend to be close to the third opening 401 to form a sheath blocking surface 404. After the external force applied to the second sheath is removed, the second sheath 30 moves toward the second opening 301 under the elastic force of the spring 50, as shown in fig. 16. Thus, after the injection needle of the present invention is used, for example, when the second sheath is pressed down again, the end of the blocking member 305 of the second sheath will abut against the sheath blocking surface 404 of the inner core 40, so that the second sheath cannot be compressed back into the accommodating space for the second time to expose the needle tube, thereby avoiding cross infection caused by accidental injury of other people by the needle after use.

As shown in fig. 9, the bottom of the needle hub 10 may be provided with a limit plane 103, from which limit plane 103 the guide engagement extends in the axial direction towards the first opening 201 and is located at the edge of the limit plane 103. After the axial rotation of the core 40 is completed, the other end of the core abuts against the limit plane 103 to prevent further axial movement of the core. The hub 10 may also be provided with a core stop 104 that interfaces with the guide mating portion, the core stop being adapted to prevent further circumferential movement of the core 40 after circumferential rotation is completed.

Further, as shown in fig. 7, the other end of the inner core 40 is provided with a boss portion 405 extending radially from the core body of the inner core. The inner core guide portion 402 extends radially from the edge of the boss portion 405 toward the hub 10 (as shown in fig. 11), and the guide engagement portion is provided radially outward of the boss portion 405 (as shown in fig. 12). The boss portion 405 has a boss top surface 4051 and a boss bottom surface 4052, and one end of the spring 50 abuts the boss top surface 4051. After the circumferential rotation of the core 40 is completed, the boss bottom surface 4052 or the core guide 402 abuts the limit plane 103.

Further alternatively, referring to fig. 9, the guide-engaging portion of the needle mount 10 may include a planar guide portion 101 and a beveled guide portion 102 extending obliquely from the planar guide portion to the limiting plane 103. As shown in fig. 12, in the mounted position of the core 40 with the needle mount, the core guide 402 mates with the planar guide 101. Based on the movement of the second sheath 30 toward the accommodation space R, the core guide 402 rotates in the circumferential direction from the planar guide 101 to the ramp guide 102 to guide the core to rotate in the circumferential direction, and the core guide 402 is adapted to move out of engagement with the ramp guide.

In one exemplary embodiment, the hub 10 may be provided with a plurality of guide mating portions 101,102, with the core limiter 104 being a core limiter groove between adjacent two of the plurality of guide mating portions, as shown in fig. 9.

As shown in fig. 9, the hub 10 may further include a sheath stop 105 that abuts the guide mating portion. The sheath blocking portion 105 has a height in the axial direction that is larger than the height of the guide fitting portion in the axial direction, and the sheath blocking portion 105 is adapted to prevent the second sheath 30 from moving toward the accommodation space R.

In one embodiment, as shown in fig. 9, the center of the hub 10 is provided with a through hole 106 through which the needle cannula 60 passes and a hub rib 107 extending from the through hole 106 in the axial direction. Referring to fig. 11, the inner wall of the inner core 40 is provided with a hub fitting portion 406 extending in the axial direction, and the hub rib 107 is fitted in the hub fitting portion 406 and adapted to axially rotate therein. Alternatively, both hub rib 107 and hub mating portion 406 have a stepped shape.

Referring to fig. 4, the one end of the first sheath 20 is provided with a base 203, the inner wall of which is provided with a transverse groove 204 circumferentially arranged. As shown in fig. 9, the one end of the hub 10 is provided with a transverse bead 108 which is arranged radially around the outer wall of the hub. When the disposable needle is assembled, the transverse ribs 108 fit within the transverse grooves 204 to fix the axial position of the hub 10 and the first sheath 20.

With continued reference to fig. 9, the one end of the hub 10 may also be provided with a hub catch 109 extending in the axial direction, the hub catch being located on the outer wall of the hub. As shown in fig. 4 and 12, the inner wall of the base 203 of the first sheath 20 may also be provided with ribs 205 extending in the axial direction, which are adapted to fit in the hub catch 109 to prevent the hub 10 from rotating circumferentially relative to the first sheath 20.

In an embodiment of the present invention, as shown in fig. 5, the one end of the second sheath 30 may be provided with a sheath limiting groove 306 formed on an outer wall of the second sheath. The inner wall of the first sheath 20 is provided with a limit bead 206 extending in the axial direction, which is adapted to fit in the sheath limit groove, as shown in fig. 10.

In an alternative embodiment, as shown in fig. 5, the sheath spacing groove 306 may include a first spacing groove portion 3061 having a triangular cross section and a second spacing groove portion 3062 having a rectangular cross section arranged along the axial direction. In this embodiment, the width of the first limiting groove portion is greater than the width of the second limiting groove portion, so that the limiting ribs 206 are inserted into the sheath limiting groove 306, thereby making the assembly of the second sheath and the first sheath easier. It should be noted that the structure and shape of the jacket limiting slot are only exemplary and are not intended to be limiting.

In an alternative embodiment, as shown in fig. 1 and 2, the disposable injection needle may further comprise a third sheath 70, the third sheath 70 externally sleeving the needle hub 10, the inner core 40, the first sheath 20 and the second sheath 30.

Alternatively, the connection between the first sheath 20 and the hub 10 may be provided with a first anti-rotation feature (e.g., a rib or protrusion, or an interference fit feature) and the connection between the third sheath 70 and the hub 10 is provided with a second anti-rotation feature (e.g., a anti-rotation rib or protrusion, or an interference fit feature).

Optionally, as shown in fig. 1 and 2, the disposable needle may further comprise a seal 80 covering the opening of the third sheath 70. Before the disposable needle can be used, the seal 80 needs to be torn and the outer sheath 70 removed to remove the internal components, thereby further preventing the needle from failing due to mishandling before it can be used.

An assembling process of an injection needle according to an exemplary embodiment of the present invention will be described below with reference to the above-described structure.

First, the needle cannula 60 is inserted through the through hole 106 of the needle hub 10, and may be fixed by, for example, an adhesive process. Needle hub 10 with needle cannula is then advanced from the bottom of core 40 and needle cannula 60 is passed through third opening 401 of the core. At this time, the inner sidewall of the inner core 40 is in contact with the hub rib 107, and the inner core guide 402 of the inner core 40 contacts the planar guide 101 of the hub 10.

Next, the spring 50 is sleeved outside the core 40. One end of the spring 50 abuts against the boss portion 405 of the inner core 40, and the other end is in contact with the stopper 305 of the second sheath 30.

Then, the assembly of the above components is placed from the bottom of the first sheath 20 into its cavity (i.e., the accommodation space R). The second sheath 30 protrudes from the first opening 201, and the hub catching groove 109 of the hub 10 is engaged with the rib 205 of the first sheath 20 so that the hub 10 and the first sheath 20 cannot be rotated circumferentially. The transverse ribs 108 of the hub 10 fit within the transverse grooves 204 of the first sheath 20 to fix the axial position of the hub 10 and the first sheath 20. The stepped surface 304 of the second sheath 30 contacts the first blocking surface 202 of the first sheath 20 under the influence of the spring 50 to reach an assembled initial state, as shown in fig. 12.

The operation of the disposable injection needle according to the exemplary embodiment of the present invention will be described with reference to the above-described structure.

When the disposable injection needle is used, the second sheath 30 moves toward the needle mount 10, i.e., toward the accommodating space R, by an external force. When the blocking member 305 of the second sheath 30 contacts the guide surface 4033 of the inner core 40, the blocking member 305 generates a pushing force against the guide surface 4033. Under this thrust force, the core 40 is rotated circumferentially, and the core guide 402 of the core 40 is gradually separated from the planar guide 101 of the needle mount 10 by the contact state until the core guide 402 is no longer in contact with the planar guide 101, as shown in fig. 13.

After the core guide 402 of the core 40 is separated from the flat guide 101 of the needle holder 10, the core 40 continues to move circumferentially under the elastic force of the spring 50 and contacts the inclined guide 102 of the needle holder 10. This causes the core 40 to move axially while rotating circumferentially, during which the blocking member 305 of the second sheath moves within the retaining groove 403 of the core 40 until the core 40 rotates to such an extent that the side walls of the blocking member 305 engage the side walls of the retaining groove 403, preventing further rotation of the core, as shown in fig. 14 and 15.

The needle cannula 60 is exposed from the second opening 301 of the second sheath 30 during the movement of the second sheath 30 toward the needle mount 10. The needle cannula 60 is exposed the longest when the second shield 30 is depressed such that its bottom surface 307 is in contact with the shield stop 105 of the needle hub 10 or the second opening 301 is lower than the first opening 201 of the first shield 20, as shown in fig. 14.

When the needle is in use, the second sheath 30 is no longer subjected to a depression. At this time, the second sheath 30 is sprung up by the force of the spring. While the second sheath 30 is moved until its blocking member 305 is separated from the stopper groove 403 of the inner core 40, the inner core 40 slides along the inclined guide 102 of the needle holder 10 under the force of the spring 50 until the inner core guide 402 or the bottom surface 307 comes into contact with the stopper plane 103 of the needle holder 10. At this time, the second sheath 30 moves axially under the force of the spring 50 until the stepped surface 304 of the second sheath 30 contacts the first blocking surface 202 of the first sheath 20, as shown in fig. 16.

In this state, the upper planar surface 407 of the inner core 40 is lower than the cavity top surface 207 of the first sheath 20. When the second sheath 30 is a transparent member, the change in the position of the core before and after use can be visually observed.

When the second sheath 30 is pressed down again, the end of the stopper 305 of the second sheath 30 is in contact with the sheath stopper surface 404 of the core 40, as shown in fig. 17 and 18, and cannot move downward any more. At this time, the needle tube 60 is lower than the second opening 301 of the second sheath 30 and cannot be exposed, and thus cannot be used for a second time.

The above description is given for the purpose of illustrating the embodiments of the present invention and is not to be construed as limiting the invention, but is to be construed as including any modifications, equivalent alterations, improvements, etc. which do not depart from the spirit and principles of the present invention.

Claims

1. A disposable injection needle comprising:

a needle mount provided with a needle cannula extending axially therethrough;

a first sheath having one end connected to one end of the needle mount to form an accommodating space between the first sheath and the needle mount, the other end of the first sheath having a first opening;

a second sheath having one end located in the accommodation space and the other end having a second opening and protruding from the first opening, a portion of the second sheath being axially slidably located in the accommodation space;

the inner core is arranged in the accommodating space and sleeved on the needle seat, one end of the inner core is provided with a third opening, and the needle tube axially extends through the third opening and is suitable for being exposed through the second opening; and

a spring adapted to provide an elastic force for axially moving the second sheath toward the outside of the accommodation space,

wherein:

the one end of the second sheath is sleeved on the inner core and is suitable for being retracted into the accommodating space against the elastic force of the spring based on the external force so as to expose the needle tube;

the other end of the inner core is provided with an inner core guide part extending in the radial direction, the needle seat is provided with a guide matching part, and the inner core guide part is matched with the guide matching part at the installation position of the inner core and the needle seat; and

the core guide portion moves along the guide engagement portion to guide the core to rotate in the circumferential direction based on the second sheath moving toward the accommodation space, and is adapted to move out of engagement with the guide engagement portion.

2. The disposable injection needle of claim 1, wherein:

the second sheath has a small diameter portion and a large diameter portion connected to each other in an axial direction, the small diameter portion and the large diameter portion forming a stepped surface at the connection, wherein the small diameter portion is adapted to protrude from the first opening to outside the first sheath, a distal end of the small diameter portion having the second opening;

the other end of the first sheath has a first blocking surface defining the first opening; and

the step surface is suitable for being in abutting fit with the first blocking surface, and the large-diameter part can be axially and slidably positioned in the accommodating space.

3. The disposable injection needle of claim 2, wherein:

the inner wall of the second sheath is provided with a blocking member extending in the axial direction;

the outer wall of the inner core is provided with a limiting guide groove extending in the axial direction; and

based on the rotation of the inner core in the circumferential direction, the blocking member enters the limit guide groove.

4. A disposable injection needle according to claim 3, wherein:

the limiting guide groove comprises a first guide groove part and a second guide groove part which are arranged along the axial direction, and the size of the first guide groove part in the circumferential direction is larger than that of the second guide groove part in the circumferential direction; and

based on the circumferential rotation of the inner core, the blocking member is adapted to rotate axially and circumferentially from the first guide groove portion to the second guide groove portion and to be blocked in the second guide groove portion.

5. The disposable injection needle of claim 4, wherein:

the end part of the first guide groove part, which is close to the second guide groove part, is provided with a guide surface; and

the end of the blocking piece is provided with a matching surface matched with the guide surface.

6. The disposable injection needle of any one of claims 3-5, wherein:

the inner wall of the second sheath is provided with a plurality of blocking pieces which are spaced apart from each other, and the outer wall of the inner core is provided with a plurality of limiting guide grooves which are spaced apart from each other; and

each of the plurality of stops enters a corresponding one of the plurality of limit channels based on circumferential rotation of the inner core.

7. A disposable needle according to claim 3, wherein two side walls of the limit groove in the circumferential direction extend to be close to the third opening to form a sheath blocking surface.

8. The disposable injection needle of claim 1, wherein:

the bottom of the needle seat is provided with a limit plane, and the guide matching part extends from the limit plane towards the first opening along the axial direction and is positioned at the edge of the limit plane;

after the axial rotation of the inner core is completed, the other end of the inner core abuts against the limiting plane to prevent the inner core from further axial movement; and

the needle seat is also provided with an inner core limiting part connected with the guiding matching part, and the inner core limiting part is suitable for preventing the inner core from further circumferential movement after the circumferential rotation is completed.

9. The disposable injection needle of claim 8, wherein:

the other end of the inner core is provided with a boss part extending radially from the core body of the inner core, the inner core guide part extends radially from the edge of the boss part towards the needle seat, and the guide matching part is arranged on the radial outer side of the boss part;

the boss part is provided with a boss top surface and a boss bottom surface, and one end of the spring is abutted against the boss top surface; and

after the circumferential rotation of the inner core is completed, the boss bottom surface or the inner core guide portion abuts against the limit plane.

10. The disposable injection needle of claim 9, wherein:

the guide matching part comprises a plane guide part and a slope guide part which obliquely extends from the plane guide part to the limit plane;

the inner core guide part is matched with the plane guide part at the installation position of the inner core and the needle seat; and

based on the second sheath moving toward the accommodation space, the core guide rotates in the circumferential direction from the planar guide to the ramp guide to guide the core to rotate in the circumferential direction, and the core guide is adapted to move out of engagement with the ramp guide.

11. The disposable injection needle according to claim 8, wherein the needle holder may be provided with a plurality of the guide engaging portions, and the core stopper is a core stopper groove between adjacent two of the plurality of guide engaging portions.

12. The disposable injection needle of claim 8, wherein the hub further comprises:

and a sheath blocking portion abutting the guide fitting portion, and having a height in the axial direction greater than a height in the axial direction of the guide fitting portion, the sheath blocking portion being adapted to prevent the second sheath from moving toward the accommodation space.

13. The disposable injection needle of claim 8, wherein:

the center of the needle seat is provided with a through hole for the needle tube to pass through, and the needle seat is also provided with a needle seat rib part extending from the through hole along the axial direction; and

the inner wall of the inner core is provided with a hub fitting portion extending in the axial direction, and the hub rib is fitted in the hub fitting portion and adapted to axially rotate in the hub fitting portion.

14. The disposable injection needle of claim 13, wherein the hub rib and the hub mating portion each have a stepped shape.

15. The disposable injection needle of claim 1, wherein:

the inner wall of the base is provided with a transverse groove circumferentially arranged;

the one end of the needle seat is provided with a transverse convex rib, and the transverse convex rib is circumferentially arranged on the outer wall of the needle seat along the radial direction; and

the transverse ribs are matched in the transverse grooves.

16. The disposable injection needle of claim 15, wherein:

the one end of the needle seat is also provided with a needle seat clamping groove extending along the axial direction, and the needle seat clamping groove is positioned on the outer wall of the needle seat; and

the inner wall of the base is also provided with a convex rib extending along the axial direction, and the convex rib is suitable for being matched in the needle seat clamping groove.

17. The disposable injection needle of claim 1, wherein:

the one end of the second sheath is provided with a sheath limiting groove which is formed on the outer wall of the second sheath; and

the inner wall of the first sheath is provided with a limiting convex rib extending along the axial direction, and the limiting convex rib is suitable for being matched in the sheath limiting groove.

18. The disposable needle of claim 17, wherein the sheath retaining groove comprises a first retaining groove portion and a second retaining groove portion arranged along the axial direction, the first retaining groove portion having a triangular cross section, the second retaining groove portion having a rectangular cross section.

19. The disposable injection needle of claim 1, further comprising:

the third sheath is sleeved outside the needle seat, the inner core, the first sheath and the second sheath.

20. The disposable injection needle of claim 19, wherein a connection between the third sheath and the hub is provided with a first anti-rotation feature and a connection between the third sheath and the hub is provided with a second anti-rotation feature.

21. The disposable injection needle of claim 19, further comprising:

and the sealing paste wraps the opening of the third sheath.